I can't tell you exactly what was changed, but it is fairly well known that there were upgrades made around 2013, along with the gearbox going from 6 speed to 8. I believe at least the timing chain guides were upgraded and the ECU and related sensor systems were changed from Denso to Bosch. According to Stuart at VAP, greater tune gains can be had with the later Bosch ECUs.

 

 

Yeah, I would not go beyond 7500 between oil changes on these engines. I'm sticking to 3000-5000 myself.

 

My 2011 XJL 5.0 liter Supercharged suffered a head gasket failure just before the warranty expired. Repairs were made by my dealer at no charge. Suffered another catastrophic engine failure while on a trip in March of this year and decided to trade the damned thing on a new Cadillac so I could get home. The Cadillac obviously doesn't have the panache of a Jaguar, but so far, so good. Drove 300 miles last Sunday so my wife could see her mother for Mother's Day and the Cadillac was comfortable and performed beautifully. So far, I have no regrets.

Dwayne

 

Not sure of all the changes but a big one for the 5.0L V-8 was the timing chain change from 6mm to 8mm chains. Still trying to pin this down but it appears to have happened somewhere during or at the end of 2013.

So I "think" the 2014 and newer V-8's have the larger improved timing gear.

Another apparently ongoing upgrade is the water pump. This is widely known and again it looks like 2014 got a better unit BUT I did see a 5th water pump part number out there so not sure Jaguar got it right yet?
I don't consider the water pump a big deal as I DIY and it's not a hard job. The biggest threat is not getting an overheating warning until it's too late and the motor is toast!

Hopefully others can post addition information as I am VERY interested in all the details. XDave is a very informed member who has posted a huge amount details. Dave Tibbs is another one and is currently rebuilding his 5.0L V-8. If you can check out what is doing it's way beyond what most of us shade-tree guys would even consider!!

The thread is up to 9 pages now and he's not done yet.
https://www.jaguarforums.com/forum/x...177468/http://
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A friend at work bought a 5 series BMW the same time I purchased the XJ. She asked me if I was worried about reliability? She has her car maintained at the dealership and has every preventive thing she can have done there. She is just over 50k and out of warranty. She blew a head gasket last week. Cost her $12,000.00! She also got new tires with the $12k. She asked her service advisor if there was anything she could have done to prevent this from happening? He said no, things just happen sometimes. When it was being worked on, I suggested having the timing chain replaced, since they had to remove it. Her service advisor said it wasn’t necessary to replace it?

 

If it is a chain and metal teeth it isn't necessary. If it is vinyl teeth or a belt, then they could have done this. I doubt I would put $12k into any car that is out of warranty. I also suspect she could have gone to a non dealer and gotten it done for 1/3rd the cost. The dealer is for warranty work only. Once a car is out of warranty, you are a fool to take it to the dealer.

 

And your otta here!.........










Just kidding